title: Cascading "Triclick" functionalization of poly(caprolactone) thin films quantified via a quartz crystal microbalance.
abstract: A series of mono- and multifunctionalized degradable polyesters bearing various "clickable" groups, including ketone, alkyne, azide, and methyl acrylate (MA) are reported. Using this approach, we demonstrate a cascade approach to immobilize and quantitate three separate bioactive groups onto poly(caprolactone) (PCL) thin films. The materials are based on tunable copolymer compositions of ε-caprolactone and 2-oxepane-1,5-dione. A quartz crystal microbalance (QCM) was used to quantify the rate and extent of surface conjugation between RGD peptide and polymer thin films using "click" chemistry methods. The results show that alkyne-functionalized polymers have the highest conversion efficiency, followed by MA and azide polymers, while polymer films possessing keto groups are less amenable to surface functionalization. The successful conjugation was further confirmed by static contact angle measurements, with a smaller contact angle correlating directly with lower levels of surface peptide conjugation. QCM results quantify the sequential immobilization of peptides on the PCL thin films and indicate that Michael addition must occur first, followed by azide-alkyne Huisgen cycloadditions.
authors.affiliation: Department of Polymer Science, The University of Akron, Ohio 44325, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Lin
authors.forename: Jukuan
authors.initials: J
authors.lastname: Zheng
authors.forename: Jiayi
authors.initials: J
authors.lastname: Yu
authors.forename: Jinjun
authors.initials: J
authors.lastname: Zhou
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Becker
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D057930:Click Chemistry; D061565:Cycloaddition Reaction; D055767:Immobilized Proteins / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009842:Oligopeptides / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D055767:Immobilized Proteins; D009842:Oligopeptides; D011091:Polyesters; C016240:polycaprolactone; C047981:arginyl-glycyl-aspartic acid